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Biomedical subjects

A Zouhar

Publications and source records attributed to A Zouhar.

At least 37 records · Page 2Linked to original sources
PubMed1985

EEG changes induced by convulsants interfering with GABAergic inhibition in rats. I. Cortical recordings.

Electrocorticographic changes induced by 3 convulsant drugs interfering with the GABA system were studied in 73 adult rats. Aminooxyacetic acid first elicited changes (periods of theta waves) nearly constantly in occipital regions. Bicuculline induced not only occipital theta waves but also groups of spikes with the same frequency in frontal regions; there was no predominance of one of these regions. 3-Mercaptopropionic acid invariably elicited groups of spikes in the frontal region as the first sign of its action. As it progressed, this rhythmic activity became generalized so that differences among the 3 drugs disappeared. Paroxysmal activity induced by the 3 drugs studied was identical. It always started with rhythmic spikes which were gradually transformed into spike-and-wave rhythm. Differences among the 3 convulsants studied were found in the very first electrocorticographic changes. Long latency to the onset of action of 3-mercaptopropionic acid and especially of aminoocyacetic acid qualifies these drugs for studies of preparoxysmal changes.

3-Mercaptopropionic Acid↗
PubMed1982

Influence of clonazepam and ethosuximide on ECoG pattern induced by metrazol during ontogenesis in rats.

Metrazol (80 mg/kg s. c.) elicited ECoG episodes of rhythmic activity the shape, frequency and localization of which depended on the age of rats. In 15- and 12-day-old animals there was a progression into sustained ictal activity. Clonazepam (1 mg/kg i. p.) exhibited excellent anti-metrazol action in adult, 25- and 12-day-old rats. The results in 15-day-old animals were inconsistent. Ethosuximide (125 mg/kg i. p.) protected sufficiently only adult and 25-day-old rats. In younger age groups only ictal activity was blocked, while metrazol-induced episodes remained untouched.

Age Factors↗
PubMed1980

Electrocorticographic activity elicited by metrazol during ontogenesis in rats.

Electrocorticographic changes induced by intraperitoneal injections of metrazol were studied in 72 male rats aged from 4 to 29 days. The initial paroxysmal signs varied according to age; 4- to 7-day-old rats: discharges of waves in the alpha and theta range; 11- to 20-day-old rats: spikes in the frontal area; rats aged 24 days and more: theta waves discharges (of about 5Hz) in the occipital area, i.e. a typical mature reaction. In 4- and 5-day-old rats, generalized seizures were manifested as slow waves only. A shift towards fast frequencies was observed during further development; a substantial part of this shift took place before the 14th day. After this age, bilateral synchrony of long-lasting seizure discharges was also present.

Aging↗
PubMed1979

Ontogenetic development of electrocorticogram in the rat.

Spontaneous electrocorticogram (ECoG) was recorded in frontal (sensorimotor) temporal (auditory) and occipital (visual) cortical regions of 86 male rats (immobilized with d-tubocurarine) aged from 3 days to adulthood. Activity which could be classified as ECoG was for the first time recorded in 5-day-old rats; it was formed by groups of slow waves with unstable frequency intermingled with periods of isoelectric line. Discontinuous ECoG activity was regularly registered even in 10-day-old rats, exceptionally in 12-day-old rats. During further maturation of the continuous ECoG an increase in frequency and an establishment of a basic rhythmic activity synchronous over both hemispheres took place, so that 25- and 30-day-old rats did not differ from the adult ones. Autocorrelagrams and power frequency spectra demonstrated a broad frequency range of the basic rhythm as well as delay in the development of occipital cortical areas in comparison to frontal areas.

Aging↗